Sina testing subtle censorship ahead of Tiananmen anniversary

Submitted by percy on Fri, May 31, 2013

What happened?

On May 31, 2013 at 7am, we observed that searching for keywords that are normally blocked, for example, “六四事件” (June 4th incident), surprisingly returned some results and no censorship notice. This temporary lift of censorship ended at 9am but started and stopped a few more times into early afternoon, as if literally somebody was flipping a switch on and off at Sina headquarters.

Update on June 2: Sina is still constatnly swtiching between those two method.

Update on June 8: From June 3-4th and onwards, Sina Weibo seems to switch back to explicit compelte block for those keywords.

Change in Tact

To understand what is happening you need to be familiar with Sina’s various censorship methods. We observed and reported last year that Sina had implemented new tactics to censor particular keyword searches. Just days before the June 4th anniversary, Sina is again tweaking its censorship mechanisms. During the morning hours of May 31, Sina completely abandoned its old style, explicit approach to censorship, which displayed a message but no search results:

“According to relevant laws, regulations and policies, search results for [the blocked keyword] can not be displayed.”

No, Sina has not suddenly decided to fully support freedom of speech. On the contrary, it would appear that Sina is using more advanced and subtler methods to censor search results. All keywords mentioned below are normally explicitly and completely blocked. But each behaved a little bit differently on the morning of May 31.

Strictly filtering

The results we received when we searched for “六四事件” (June 4th incident) showed that the first page of results displayed not all results but carefully selected results. While the first results page seems to indicate that there are more than 50 pages of results, no results are shown when you click through to the next page or any page beyond the first. This censorship tactic was also employed last year for “香港” (Hong Kong) (Solidot story in Chinese).

Keyword example: “六四事件”(June 4th incident)

Delayed censorship

When testing the delayed censorship tactic, we conducted two simultaneous searches of similar keywords, one sensitive and one non-sensitive. In the case of searching for results for “六四” (June 4), we used “五七” (May 7) as a control group, to be sure that search results were indeed intentionally delayed. As suspected, results for “五七” (May 7) displayed posts that were ten minutes old while the most recent June 4 posts were several hours old.

This indicates a marked improvement on Sina’s time delay censorship mechanism. Previously the default time delay was seven days. It is likely that many Sina Weibo users would find this time delay to be odd but could attribute this to a bug or a glitch in the system. With today’s hours-long time delay, most users will likely think that discussion around this topic is ongoing.

This is an example of censorship at its worst - users suspect their search term might get blocked before they search but instead of a censorship notice they are led to believe that what they are searching for is not sensitive plus not many people are saying anything interesting about the keyword anyway.

A good example of this can be found when searching for “天安门事件” (Tiananmen incident). The current search results do in fact bring up quite a bit of information about an incident which occurred in Tiananmen Square - in 1976.

Implicit complete censorship

Sina now returns a fake “Sorry, no results can be found” message instead of the normal censorship message that we have come to at once love and hate: “According to relevant laws, regulations and policies, search results for [the blocked keyword] can not be displayed.”

Keyword example: “64事件” (64 incident)

Implicit semi-censorship

Sina returned a partial censorship notice from page 2 onwards. The first page looks completely normal, leading users to believe that there are no decent search results for that keyword - why continue searching?

Keyword example: “天安门大屠杀”

V user only censorship

Some relatively low level sensitive words appear to be totally uncensored in this system. Is this the beginning of successful long tail sensitive keyword search on Sina Weibo?

Update: Earlier we said that some keywords appear to be completely uncensored. We have to admit that Sina even fooled us. Actually, all search results come from V users only. V users on Sina are like verified account on Twitter. Those users are more likely to follow the rules as they might face revoke of V status or block of account.

More Blog Posts

Thu, Nov 24, 2016

Facebook is considering launching a censorship tool that would enable the world’s biggest social network to “enter” the China market. Sadly, nobody will be surprised by anything that Mark Zuckerberg decides to do in order to enter the China market. With such low expectations, Facebook is poised to usurp Apple as China’s favorite foreign intelligence gathering partner. If the company launches in China using this strategy they will also successfully erase any bargaining power that other media organizations may hold with the Chinese authorities.

Tue, Jul 05, 2016

There is a commonly held belief in China that if you have a VPN that works then you should keep quiet about it. In terms of freedom of access to information, the problem with this approach is that access to knowledge suddenly is a secret. Today we are launching a project that we hope will destroy that model.

Our newest website, Circumvention Central (CC), aims to provide real-time information and data about circumvention solutions that work in China. Since 2011, we have been collecting data about blocked websites in China and now we will add data about the effectiveness of VPNs and other circumvention tools.

We are launching CC with four main objectives in mind.

Our first objective is to help to grow the number of Chinese who circumvent censorship restrictions in China. By sharing our information and data about these tools, we hope to show a wider audience which circumvention tools are working.

Our second objective is to improve the circumvention experience for users in China by bringing transparency to tool performance. We will measure these tools on speed (how quickly popular websites are loaded) and on stability (the extent to which popular websites load successfully).

After Google found these unauthorized certificates, both Google and Firefox revoked its trust in CNNIC a few days later, a development we at GreatFire.org have adovacting forsince2013. Apple and Microsoft on the other hand, did not revoke their trust in CNNIC, nor did they make any announcements regarding the security compromise.